Molds

Chris Bishop, AEHF

Molds are present everywhere–indoors and outdoors. They serve an important, positive role in nature, helping to break down organic matter, but they have also been identified as a major contributor to seasonal and perennial allergic rhinitis and other health problems, some of which can be severe and even life-threatening. Although thousands of molds exist, only a few dozen different types have so far been identified as significantly affecting human health. This article identifies these and answers commonly asked questions about mold:

What is mold? Where does mold grow? Mold and mildew can grow anywhere–indoors or outdoors–wherever there is enough surface moisture to keep them alive. They can be found in every type of climate and in every social and economic condition. They live where moisture, oxygen, and other chemicals are present. They can be found on the surfaces of objects, within pores, and inside deteriorated materials.          Indoors Molds can be found in damp basements, in poorly ventilated closets, and behind baseboards and walls. Molds can grow behind peeling wallpaper. They thrive in bathrooms (especially shower stalls and walls), hot tubs and jacuzzis, the laundry room (including dirty clothes and improperly vented dryers), and in kitchens and food storage areas, including the refrigerator (particularly frost-free refrigerators) and its drain pan. Dirty dishes, soiled trash cans and compactors, garbage disposals and water traps may all harbor mold as may air conditioners (their drain pan, duct work, and vents), vaporizers, and humidifiers. Mold may also be present in mattresses, upholstered or stuffed furniture, feather and old foam rubber pillows, any moist carpets or rugs, and in heavily draped or double-paned windows. Worn clothing and leather products too may contain mold, as may kitty litter and bird cages. Mold may be present on male animals or in chimney swift droppings or feathers. Roof or plumbing leaks and unsealed concrete slabs can also harbor mold as can water standing in or under a house. Additionally, the stalks and leaves of indoor house plants, along with the dirt they grow in, can support mold growth.   Many building materials are suitable nutrient sources for mold growth. These include cellulose substrates such as paper and paper products, cardboard, ceiling tiles, wood and wood products, and other substrates such as dust, paints, wallpaper, insulation materials, drywall, carpet, and fabrics.

Specific areas of high mold growth include antique shops, green houses, saunas, farms, mills, construction areas, flower shops, bakeries, breweries, barns, dairies, and summer cottages.

         Outdoors Molds can be found on dead and dying vegetation such as fallen leaves, straw, grains, and wood. They can be present in moist, shady areas, on rotting leaves and logs, and in certain grasses and weeds. They may grow in soil or on debris and various moist surfaces. They may be found on the leaves of shrubs and other plants that grow against a house or in standing water. In gardens, molds can be found in compost piles and on certain grasses and weeds. Some molds attach to grains such as wheat, oaks, barley, and corn, making farms, grain bins, and silos likely places to find mold. Neglected gutters around the house and poor drainage of foundation water can also spawn mold growth.

Outdoor molds tend to be bothersome from spring to late fall, and mold counts tend to peak in the afternoon (not in the morning like pollens).

What do molds need to thrive? Molds are elusive and will be more prevalent at different times of the day or night, depending on their type. Generally, though, in order to thrive, molds need (1) food, (2) a fungal spore, (3) moisture (water), and (4) preferably warm temperatures (40° to 100° F) with humidity above 60%.        (1) Food

        Food for mold can be any organic material.

       (2) Fungal spores

The spores of fungi that become mold or mildew are always present in the air and on objects. When the temperature and moisture in the environment are suitable for germination, the fungus spore bursts and grows into a thread-like filament called a "hyphae." Using the object it is growing on as a food source, the hyphae forms a mass, called a "mycelium," and within a short time begins to produce spores. At maturity, spore sacs burst and release spores, which eventually land on other material and begin the reproductive cycle again.

(3) Moisture–liquid water

Liquid water comes into the house via a leaky foundation or from leaks or breaks in plumbing. These conditions can cause flooding and quick saturation of indoor organic materials. If left for more than one to two days, these conditions allow mold growth to commence. During growth, fungal colonies can produce gases, known as "volatiles" which are the musty or mildewy odors often associated with damp basements.

       (4) Warm temperatures and excess relative humidity While molds typically thrive at temperatures above 70°F and a relative humidity (RH) of greater than 70%, some molds can grow at temperatures as low as 50°F and an RH as low as 45%. Humid indoor air results when hot air comes in contact with a cool surface and water condenses to form "dew." This usually happens in buildings that have poorly insulated exterior walls and windows during winter. It also happens to exposed cold pipes in the summer. How do I identify the cause of mold in a heating environment? In heating climate regions, mold and mildew are commonly found on the exterior wall surfaces of corner rooms. This is because an exposed corner room is likely to be significantly colder than its adjoining rooms, and, as a result, it will have a higher relative humidity (RH) than other rooms with the same water vapor pressure, thus creating conditions that will promote and sustain mold growth.

The presence of mold and mildew in a corner room suggests that the relative humidity next to the room surfaces is above 70%. However, too cold of a temperature or too much moisture (high water vapor pressure) in a room may also cause high (greater than 70%) relative humidity and conditions that will support mold growth. The following two scenarios show how this can happen.

The amount of moisture in a room can be estimated by measuring both the relative humidity and the temperature at the same location and at the same time. For example, in the middle of a room the relative humidity may be 30% and the temperature 70° F. This low RH at that temperature would indicate that the water vapor pressure (or absolute humidity) is low. High surface RH in this room would likely be due to room surfaces that are "too cold." Thus, in this scenario, temperature would be the dominating factor, and to decrease the RH and control mold growth, the temperature at cold room surfaces would need to be increased.

In another scenario, the RH measured in the middle of a room might be 50% and the temperature 70°F. In this room, the higher RH at that temperature would indicate that the water vapor pressure is high and a relatively large amount of moisture is in the air. The high surface RH would probably be the result of air that is "too moist." Thus, in this scenario, humidity would be the dominating factor, and strategies employed to decrease mold growth would involve decreasing the moisture content of the indoor air.

How do I identify the cause of mold in a cooling climate? The problems of mold and mildew can be as extensive in a cooling climate as in heating climates. In both climates, the same principles apply: either surfaces are too cold, moisture levels are too high, or both.

A common example of mold growth in a cooling climate can be found in rooms where conditioned "cold" air blows against the interior surface of a hot exterior wall. This condition, which may be due to poor duct design, diffuser location, or diffuser performance, creates a cold spot at the interior finish surfaces. A mold problem can occur within the wall cavity as hot outdoor air comes in contact with the cavity side of the cooled interior surface. This is a particular problem in rooms decorated with low maintenance interior finishes (for example, impermeable wall coverings such as vinyl wallpaper and high-gloss paints), which can trap moisture between the interior finish and the gypsum board. Mold growth can be rampant when these interior finishes are coupled with cold spots and exterior moisture.

How do molds effect air quality and the environment? Molds are a source of indoor air pollution in climates as diverse as the warm and humid Gulf Coast and the cooler Pacific Northwest. Molds can cause discoloration and odor problems and deteriorate building materials. They also can cause significant health problems in susceptible human beings. How do molds affect human health? After pollens, molds are the leading cause of outdoor airborne allergies, which can recur year-round. Some of the most common symptoms of those sensitive to molds include nasal stuffiness, eye irritation, wheezing, cold and flu-like symptoms, rashes, conjunctivitis, inability to concentrate, and fatigue. Mold exposure has also been associated with asthma onset. Symptoms usually disappear when the mold is removed. However, under certain conditions, exposure to mold can cause serious health problems. Some people with chronic illnesses, such as obstructive lung disease, for example, may develop mold infections in their lungs. Also, some people exposed to large amounts of mold at work, such as farmers working with moldy hay, may develop even more severe reactions, including fever and shortness of breath. Some molds are toxic, producing chemicals called "mycotoxins," which in large doses may affect human health, usually by causing allergy-like symptoms such as watery eyes or eye irritation, runny nose and sneezing or nasal congestion, wheezing and difficulty breathing, aggravation of asthma, coughing, itching, or rashes.

Other health problems that have been linked to mold exposure involve the odors produced by mold "volatiles" during the degradation of substrates. These have been discovered to irritate mucous membranes, and they have been associated with a number of symptoms–from headaches and nausea to fatigue–in individuals exposed to them. For those suffering from multiple chemical sensitivities, the simple presence of these microbial volatile organic compounds (MVOCs) can trigger a reaction just as strong and serious as exposure to chemical VOCs.

Fungi or microorganisms related to them may cause other health problems similar to allergy. Some kinds of Aspergillus especially may cause several different illnesses, including both infections and allergy. These fungi may lodge in the airways or a distant part of the lung and grow until they form a compact sphere known as a "fungus ball." In people with lung damage or serious underlying illnesses, Aspergillus may grasp the opportunity to invade and actually infect the lungs or the whole body.

In some individuals, exposure to these fungi can also lead to asthma or to an illness known as "allergic bronchopulmonary aspergillosis." This latter condition, which occurs occasionally in people with asthma, is characterized by wheezing, low-grade fever, and coughing up of brown-flecked masses or mucous plugs. Skin testing, blood tests, x-rays, and examination of the sputum for fungi can help establish the diagnosis. Corticosteroid drugs are usually effective in treating this reaction; immunotherapy (allergy shots) is not helpful. The occurrence of allergic aspergillosis suggests that other fungi might cause similar respiratory conditions.

Inhalation of spores from fungus-like bacteria, called "actinomycetes," and from mold can cause a lung disease called "hypersensitivity pneumonitis." This condition is often associated with specific occupations. For example, farmer’s lung disease results from inhaling spores growing in moldy hay and grains in silos. Occasionally, "hypersensitivity pneumonitis" develops in people who live or work where an air conditioning or a humidifying unit that is contaminated with these spores emits them.

The symptoms of "hypersensitivity pneumonitis" may resemble those of a bacterial or viral infection such as the flu. Bouts of chills, fever, weakness, muscle pains, cough, and shortness of breath develop 4 to 8 hours after exposure to the offending organism. The symptoms gradually disappear when the source of exposure is removed and the area properly ventilated. If it is not removed, workers having to be in those contaminated areas must wear a protective mask with a filter capable of removing spores or change jobs. If "hypersensitivity pneumonitis" is allowed to progress, it can lead to serious heart and lung problems.

Also, air with a high concentration of fungal spores of a number of different types of molds may contain toxins that, when breathed over a long period of time, may result in a kind of poisoning. Stachybotrys atra, a mold that is commonly found on wet cellulose products (for example, drywall) and is causing growing concern among physicians, is one of these molds. In one recent study, it was linked to lung bleeding in infants. This mold has also been linked to sudden infant death syndrome and to central nervous system symptoms such as personality changes, sleep disorders, and memory loss.

What are the routes of mold exposure? Mold exposure can occur through several different routes. Spores or fragments, for example, may be inhaled through the nose and into the lungs where they cause allergic reactions or asthma. Also, exposure can occur when individuals ingest mold-contaminated material or when they directly handle it. The dose of exposure to toxic mold and the individual’s susceptibility make the difference in the kind and severity of his or her reactions.

Because of the adverse effects that mold and mildew can have on people, those with known allergies, asthma, or other respiratory problems are well-advised to stay away from infested areas. Aside from the fact that many fungi will seriously irritate and inflame lungs or cause skin and eye irritation and infections, prolonged exposure to germinating molds in closed areas (which exist in many library collections, for example) can damage the lungs, mucous membrane, cornea, respiratory tract, stomach, intestines, and skin.

What do I do if I have symptoms of mold exposure? What factors contribute to increasing indoor mold counts?
A variety of factors contribute to increasing indoor mold counts, including the following:
How do I locate mold in my home? How do I decrease my exposure to INDOOR mold? Indoors, you do not want just to avoid molds; you want, ideally, to prevent their growth and to rid your home of them when they are discovered. Controlling the growth of indoor mold, however, is complicated by three factors: (1) temperature settings are based on human comfort levels. Temperatures that are good for controlling mold may be uncomfortable for human occupants; (2) mold spores are omnipresent inside and outside. As soon as conditions are right, they begin to grow and spread; and (3) nutrients for mold growth are always available. They are present in the construction materials and furnishings used in the home.

Of the ingredients necessary for mold growth–a warm temperature, a mold spore, nutrients, and moisture–the last is the single most important and the only one that we can control for. Therefore, to decrease the presence of indoor mold, liquid water and excess humidity must be eliminated through appropriate clean-up, repair, and installation of ventilation equipment and heating/cooling systems.

Following are some general guidelines for decreasing indoor mold:

Modulate the moisture.

Decrease moisture and the food source for mold on all surfaces.

Keep indoor humidity below 60% and, ideally, between 35 to 45%. Continuously running the air conditioning or a dehumidifier can lower moisture enough to prevent mold growth–if these are kept clean. Filters on both should be scrubbed or changed regularly. In the central air system, high performance electrostatic air filters that contain media treated with an anti-microbial inhibitor should be used. All components of the heating and cooling system should be inspected regularly. Ductwork and filters should be kept clean, and water should not be allowed to stand in condensate pans. A professional fiberoptic borescope examination of the ductwork may be essential. Dehumidifiers, humidifiers, and air conditioning condensing units should be regularly cleaned with a disinfectant such as chlorine bleach.

Part of eliminating indoor condensation can involve increasing the amount and coverage of insulation that is applied to the exterior walls. This will raise the temperature of the interior surface nearer to that of room air. Furniture and wall hangings and books shelves should not be in direct contact with exterior walls because moisture can get trapped behind them and become a breeding ground for mold. Also, cold water pipes should be wrapped with proper pipe insulation to prevent dripping.

CAUTION: Fungal contamination on drywall or paper suggests stachybotrys chartarium/atra. This is a serious problem. To confirm its presence and discover the best method of clean up, you should check with your local health department or other professional with expertise in indoor fungi and health.

The home should be well-ventilated, especially those areas where moisture tends to build up like kitchens, bathrooms, laundry rooms and basements. The use of air conditioners, dehumidifiers, and fans can reduce indoor moisture.

Areas under and around the house should be drained and ventilated.

Moisture leaks in roofs, walls, and plumbing should be repaired.

The home should be regularly inspected for dry rot, and if it is found, it should be repaired immediately.

Crawl spaces should be sealed off or black plastic should be used to prevent the spread of mold in them.

If carpeting or furnishings become wet, they must be quickly and thoroughly dried or discarded.

Surface areas should be kept clear of food for mold. If mold growth occurs, a disinfectant can be used to get rid of it. Appropriate disinfectants include 1 cup of bleach to 10 cups of water or Safety Clean or Super Clean.

Closets should be ventilated and have lights installed in them. If the closet is damp, the light should be continuously burned in it.

Old clothing stored in the attic should be cleared out.

Mildewed scrapbooks, photos, letters, books, magazines, and newspapers should be discarded.

Moldy carpet should be removed.

Any moldy stored items should be discarded.

Any moldy, damaged stuff, including old shoes, mattresses, and furniture, should be removed.

The number of houseplants should be limited. Mold grows in the soil and on the bark and leaves. Moving them can release spores into the air. Also, indoor plants should be repotted outdoors.

A HEPA vacuum cleaner should be used to clean carpets and furniture frequently.

To prevent mold growth, areas can be treated with X158, Zepharin, Impregon, or DMC-3.

Window moldings throughout the house should be regularly cleaned with an appropriate disinfectant.

Installing a heating/ventilation/air conditioning (HVAC) system with humidity control can solve the three problems of humidity, temperature, and air circulation simultaneously. These systems, however, are not easy to install or maintain, and they are expensive. These systems assist in preventing mold growth, and they stabilize the environment, eliminating the distortion of materials that results from fluctuating temperature and humidity. (Additionally, HVAC systems help control insect infestations, and they slow down deterioration in materials affected by acid, light, and pollution [such as books]). Fans can improve circulation. They should be placed near outside walls and close to floor level. Portable dehumidifiers can be used for localized mold problems, but they are not as effective in controlling humidity as a centralized HVAC system with humidity control. Fans and vents in attics increase air circulation by pulling air through the building. These are a particularly useful strategy when windows must be left open. Desiccants (such as silica gel) can be used to absorb moisture in humid environments, but they are dangerous if ingested, so they should not be used where children can reach them. They are most useful with localized problems–particularly, those in a contained, small, enclosed space.

Sunlight and ultra-violet radiation, generally, inhibit mold growth.

How do I deal with mold in specific areas of my home?  
Along with germs, mold and mildew thrive in bathrooms and kitchens where there are plenty of "food sources," including bathtubs, showers, sinks, tile grout, countertops, shower curtains, faucets, garbage cans, diaper pails, litter boxes and animal cages. Basically, you have three options in the battle against these contaminants. You can remove them, kill them, or prevent them. Generally, the following guidelines apply.

To remove mildew and its stains, commercial products labeled "mildew removers" can be used, providing the following cautions are observed:

They should only be used in a well-ventilated area.

An asthmatic person should not use them.

The common course of treatment is to spray the mildew, wait a few seonds to let the cleaner penetrate, and then wipe the area clean.

Most of these products contain bleach. Therefore, they should not come in contact with clothes, fabric, carpet, wood, rubber, or painted or papered surfaces.

To kill (disinfect) mold and mildew, commercial cleaners are also available. The product’s label will say if it is intended to control or prevent mold and mildew growth. What you should know about these products is the following:

Disinfectants kill germs, but they do not clean surfaces.

Disinfectant (antibacterial) cleaners both clean and kill germs.

Some disinfectants and disinfectant cleaners also kill mold and mildew. The only way to know about a specific product is to read its label.

To prevent mold and mildew growth, disinfectants or disinfectant cleaners must be used two to three times per week:

The surface should first be cleaned to remove any mildew stains.

Then a disinfectant product should be used.

REMEMBER: Safety first! DO NOT mix different cleaning products together. Hazardous gases can be produced.

The bathroom

The warm, moist atmosphere in the bathroom is ideal for growing mold and mildew. To help prevent this growth, leaks must be repaired. Exhaust fans should be used. Overall air circulation and light should be increased. And all surfaces should be kept clean and dry.

Bleach (1 cup bleach to 10 cups of water) can be used to scrub damp areas that invite mold growth: bathroom fixtures, floors and walls, the shower curtain, tile, the area behind the toilet, and window moldings.

Some shower curtains are mildew resistant and may be helpful in keeping mildew at bay. If a shower curtain is made of fabric or vinyl, however, it needs to be periodically washed with hot water, laundry detergent, and bleach.

Fabric shower curtains

Most fabric shower curtains can be laundered using detergent and liquid household bleach, but the care label directions for the curtain should be read before cleaning it.

Before the fabric shower curtain is washed, an inconspicuous corner should be tested to insure that the bleach is safe for the fabric. Then heavily mildewed areas should be presoaked in ¼ cup liquid household bleach and 1 gallon of water. If liquid bleach is not safe for the fabric, a solution of color-safe bleach and water can be substituted, following the directions on the bleach label.

Vinyl shower curtains

Before vinyl curtains are washed, heavily mildewed areas should be scrubbed with liquid bleach or a mildew remover.

Vinyl curtains should not be dried in the dryer. They should be taken from the washer and hung on the shower rod to drip dry.

An exhaust fan or open window should be used to remove moisture after showering.

A sponge or squeegee should be used to wipe down damp surfaces and bathroom walls and stalls after showering.

Shower doors and curtains should be kept open after the shower has been used to allow the shower walls to air dry.

Mildew can grow on soap scum (that "ring around the tub"), so a soap scum remover should be used to clean away these deposits.

Some commercial products are available for spraying on shower walls and curtains to prevent mildew growth.

Bathrooms should be washed with a mold-preventing or mold-killing solution at least once a month.

Mold on bathroom surfaces should be cleaned with a fungicide. Special attention should be paid to the tile and the areas around plumbing pipes and fixtures.

The bathroom should be ventilated with an exhaust fan or by opening a window to reduce humidity and opportunities for mold and mildew growth.

Items on which mold can grow should be removed from the bathroom.

Bleach or lysol should be used to clean areas where mildew thrives–tile grout, shower curtains and doors, the toilet tank, and window sills.

A fan vented to the outside should be installed.

Diaper pails should be kept clean with a disinfectant (antibacterial) cleaner or liquid household bleach.

Mold can grow on towels and bath mats. After each use, these should be loosely hung to air dry, and they should be laundered at least once a week.

The kitchen

1. Appliances

The stove/cooking areas should be vented to the outside.

The refrigerator drip pan should be checked often. If it contains water, it should be emptied, cleaned, and dried.

The refrigerator sides should be checked for excess moisture.

2. Under-sink Cabinets

Under-sink cabinets should be kept clean and dry.

Under-sink cabinets should be cleaned using a disinfectant (antibacterial) cleaner formulated to kill mildew (read the label).

3. Countertops

Countertops should be kept clean and dry.

4. Sinks

Faucets and handles should be kept dry.

A nonabrasive, all-purpose or disinfectant (antibacterial) cleaner should be used to clean sinks.

REMEMBER: Plumbing leaks or condensation can grow mold and mildew. Bathroom fixtures and pipes should be checked regularly for leaks, and, when found, they should be promptly repaired.

5. Floors

A floor cleaner or a nonabrasive, all-purpose cleaner should be used to clean vinyl or ceramic tile.

To avoid a "cloudy" residue, a no-rinse product should be used to clean the floors or a rinse should be applied after each cleaning.

Wall-to-wall carpeting should not be used in the bathroom. It holds moisture and cannot be thoroughly dried.

The laundry

The clothes dryer should be ventilated to the outside.

Damp clothes should not be left to sit in the washing machine. They should be immediately dried.

The bedroom

An air purifier can be used in the bedroom to reduce mold spores.

Children should not be allowed to eat in the bedroom.

Mold growth can be reduced by cleaning window frames, books, leather products, and wood paneling.

A low watt light bulb, left on all the time, can help reduce mold growth in closets.

Damp shoes and boots stored in a closet are a source of mold. They should be left outside to dry thoroughly before they are put away in the closet.

Bedrooms should be kept free of clutter, plants, fish tanks, and books.

Closet and bedroom doors should be kept closed.

Walls should be painted with a brand of paint that contains a fungicide (check the paint can label).

To prevent mold growth, walls should be primed with a fungicide containing primer before wallpaper is hung.

Bedroom carpet should be replaced with smooth flooring that can be wet mopped weekly with water and a mold retardant rinse.

Bedroom windows should be kept closed.

Furnace outlets from a forced air furnace should be closed off with aluminum foil and sealed tightly, or they should be covered with several thicknesses of damp cheesecloth, which should be changed every two weeks, or an electrostatic air filter should be used.

The basement
 

                 The crawl space

                        Crawl spaces should be ventilated.

How do I get rid of mold?

       
      Some chemicals can kill mold, but most are harmful to people and the environment. The only safe and effective way to get rid of mold is to modify the environment that contributed to its development in the first place. This means keeping room temperatures within 65° - 70°F and the relative humidity within 45%-65%.
How do I clean up areas contaminated with mold?
      REMEMBER: Chemicals are dangerous, and there is no such thing as safe large-scale treatment. This is why environmental control is so important.

      Mold can be effectively cleaned with a mold and mildew solution such as Lysol, Clorox, or X-14. Areas being cleaned with these solutions should be properly ventilated, and if you react to molds, you should wear a tight-fitting mask that securely covers your mouth and nose.

      If you find mold in your ducts, filters, or heat-exchange coils in your HVAC system, these should be replaced or cleaned with a mold-killing household cleaner.

      After water damage, you must decide whether or not to keep or discard soaked materials. Generally, all materials which manifest mold growth or smell musty or mildewy should be removed or discarded. Small areas may be washed with 1 part chlorine to 2 parts water and rinsed thoroughly.
       

Can I safely clean mildew from mattresses, rugs, and upholstery?
       
      Again, at the AEHF, we recommend erring on the side of caution and discarding any water damaged materials that show signs of mold or mildew growth. If you want to try to keep items such as mattresses, rugs, and upholstery and clean them, the following instructions from Michigan State University Extension may be useful:

      Remove loose mold from outer coverings of upholstered articles, mattresses, rugs, and carpets by brushing with a broom. Do this outdoors, if possible, to prevent scattering mildew spores in the house. Wash the broom before re-using it.

      Run a vacuum cleaner attachment over the surface of the article to draw out more of the mold. Remember that the mold spores are being drawn into the bag of the vacuum cleaner. If the vacuum has a disposable bag, remove and dispose of it immediately. If not, empty the bag carefully (preferably outdoors) to avoid scattering mold spores in the house.

      Do everything conveniently possible to dry the article–use an electric heater and a fan to carry away moist air. Sun and air the article to stop mold growth.

      If mildew remains on upholstered articles or mattresses, sponge lightly with thick suds of soap or detergent and wipe with a clean, damp cloth. In doing this, get as little water on the fabric as possible so the filling does not get wet.

      Another way to remove mildew on upholstered furniture is to wipe it with a cloth moistened with diluted alcohol (1 cup denatured or rubbing alcohol to 1 cup of water). Dry the article thoroughly.

      Sponge mildewed rugs and carpets with thick suds or a rug shampoo. Then, remove the suds by wiping with a cloth dampened with clear water. Dry in the sun if possible.

      Use a low-pressure spray containing a fungicide to get rid of mildew. Respray frequently, especially in localities where mildew is a major problem.

      If molds have grown into the inner part of an article, send it to a reliable disinfecting and fumigating service. Such services are often listed under "Exterminating and Fumigating" or "Pest Control" services in the yellow pages of the telephone directory.
       

How do I rid my home of mold or mildew odor?
       
      Charcoal and/or baking soda can be used to remove the odor of mold, if the treatment has not done so. Simply place briquettes and/or bowls of baking soda in the area to absorb odor. Do not try to wipe away mold with charcoal or baking soda.
What general strategies can I use to avoid molds?
       
      Avoid exposure to mold in damp places such as wooded areas, barns, basements, and saunas.

      Wear a tight-fitting face mask if you can’t avoid moldy places.

      Don’t use humidifiers and vaporizers because they will increase humidity in the room and create a favorable environment for mold growth. If you must use a humidifier, clean it daily to prevent mold growth.

      Change water in the dehumidifier frequently, and clean the dehumidifier often.

      Paint damp areas with mold-inhibiting paint.

      Remove stuff mold tends to grow on: old musty books, plants, mildewed carpets.

      Spray rooms with air conditioners with mold killing sprays if they begin to smell musty.

      Reduce the number of house plants and terraniums.

      Carpet should never be used in areas where persistent moisture is present.

      In areas where flooding has occurred, prompt cleaning of walls and other flood-damaged items with water mixed with chlorine bleach, diluted four parts of water to one part bleach, is necessary to prevent mold growth.

      REMEMBER: Never mix bleach with ammonia.

      Any porous material in a building that has been microbially contaminated should be discarded; disinfection is rarely effective. Contaminated insulation, ceiling tiles, and rugs must be removed.

      Smooth surface materials that have become contaminated can be cleaned with a biocide.

      If a mold/mildew problem exists, the moisture source must be controlled or abated.

      Discard moldy items.

      Ventilate the home well. Modern tightly insulated houses prevent the escape of moisture and increase mold growth.

      Ventilate kitchens and bathrooms properly.

      Filter household air: (a) add electronic filters to forced central air heating and cooling systems to trap mold spores; (b) using room size air conditioning with high efficiency particulate air filters may help eliminate mold spores, increase air circulation, and reduce humidity.

      Clean humidifiers, dehumidifiers, and air conditioners regularly to prevent mold growth. Change filters often.

      Eliminate plants, vaporizers, and aquariums from your home because they favor mold and mildew growth by raising indoor humidity.

      Reduce the number of mold spores that may enter the home by repotting plants outdoors, removing piles of leaves and mulch, and cutting back tress and brush that overhang the house.

      Locate and repair leaky pipes, clogged drains, or bad water drainage systems beneath the ground surrounding the home.

      Eliminate sources of dampness.

      It is through undiscovered or ignored water damage problems that fungi can become a very serious indoor air quality and health issue. Therefore, all water leaks should be immediately repaired. Water-damaged ceiling tiles should be immediately replaced. Heavily water-damaged sheetrock and carpet should also be immediately removed and replaced. It is virtually impossible to clean these materials once they have become heavily saturated with water.

      Possible solutions to mold problems include preventing hot, humid exteror air from contacting cold interior finish; eliminating the cold spots by relocating ducts and diffusers; ensuring that vapor barriers, facing sealants, and insulation are properly specified, installed and maintained, and increasing the room temperature to avoid overcooling.

      Modify buildings or their internal environments to prevent mold outbreaks: by doing the following:

      Don’t shelve books directly against an outside wall. Due to temperature and humidity differences between inside and outside environments, moisture may develop along walls. Allowing air to circulate against the walls will enable the moisture to evaporate.

      Keep the quantity of indoor plants to a minimum and don’t allow indoor planted areas.

      Waterproof basements and walls below ground level. And use water-sealant paint on floors and walls.

      Place or adjust outside gutters and drains so that water does not collect near the outside walls. Check gutters and drains regularly to avoid clogs. Place lawn sprinkler systems so that they do not soak outside walls.

      Regularly inspect your home for mold or mildew. This will allow you to catch any infestation before it becomes large. And continue to monitor potentially hazardous areas until the environment can be stabilized in an appropriate state.
       

How do I decrease my exposure to OUTDOOR mold?
       
      To decrease your exposure to outdoor molds, you must avoid areas that are likely to harbor them:

      People with mold allergies are more likely to have problems at the beach or in the woods because hotels, homes, and cabins there tend to be very damp. These areas should be avoided along with damp cellars, barns, lumber mills, granaries, antique and thrift shops, and bargain sales in musty basements and garages.

      Avoid wooded areas. If you must go camping in the woods, wash your sleeping bag in very hot water before leaving home. Search for a relatively clear spot away from rotted logs and vegetation.

      Don’t play or work with soil or sand.

      Avoid soil, compost piles, and hay fertilizers, all of which are sources of mold.

      Don’t cut damp grass.

      Don’t rake damp leaves and debris–you’ll stir up mold growth.

      Ideally, totally avoid gardening, cutting grass, and raking leaves, all of which kick up mold allergens. If you must do these tasks, wear a face mask and complete your work in the morning before mold counts peak.

      Leaves, clippings and compost, all of which can harbor mold, should be removed from around the house.

      Keep shrubs and grass trimmed from around the foundation of the house.

      Prune and cut trees to increase sun exposure.

      Reduce lawn and home shade. Sunshine dries some of the moisture and dampness that helps mold grow.

      Avoid outdoor activities on windy and rainy days when weather conditions stir up and spread molds.

      If you must be outdoors, wear a mask to avoid molds.

      Compost with care. Wear a tight fitting dust mask when "turning" a compost pile to keep from breathing in molds that can become airborne. And locate the compost pile away from the house.

      Keep house gutters and drains clean. Blockage encourages mold growth.

      Keep garbage cans clean and secure.
       

Conclusion
       
      Maintenance of proper environmental conditions will prevent mold growth. If mold growth does occur, a relatively gentle form of cleaning along with improving the environment will solve the problem in most situations.
Common molds found in the home, office, and school
       
      Alternaria: a fungus that grows as a parasite on both plants and plant matter. The toxic spores can easily become airborne, causing symptoms in individuals who have allergies to airborne spores. Alternaria is an agent for hypersensitivity diseases and a parasite in infections of skin lesions, soft tissues, and nails.

      Aspergillus: a common fungus that can be found in soil and on damp hay, grain, sausage, and fruit. It is a known aero-allergen, and it is the most common cause of respiratory disease in man. It can be an agent for hypersensitivity diseases. It is also an opportunistic pathogen that can cause infections, and it has been identified as a parasite in skin lesions, soft tissues, and nails.

      Basidomycetes: a class of parasite fungi that grow mainly on grain plants. This group includes rust, puff balls, smut, mushrooms, and jelly fungi. They are not a major health threat, as they are most commonly found outdoors.

      Botrytis: a fungus that is commonly found in areas of low ventilation with high relative humidity. It has a toxic odor like ammonia. Usually, it is an airborne fungus that that is similar in appearance to yeast.

      Candida albicans: an airborne yeast that is universally distributed and can be toxic. It is found in soil, feces, and nasal passages. Many health experts consider it to be a bacteria, rather than a fungus.

      Cephalosporium: a fungus that is found in damp soil. It is a widespread saprophyte on fruits, leaves, and rotting matter.

      Chaetomium: a fungus that is usually found in the soil. It also grows well on damp paper, fabric, and straw. It elicits an allergenic response in a moderate number of mold-sensitive individuals.

      Cladosporium (or Hormodendrum): a common fungus that is a known aero-allergen. It is usually associated with plants, wood products, and leather goods. The spores are easily made airborne and as such are a common cause of respiratory problems and allergic reactions. It can also be an agent for hypersensitivity diseases, and it is a parasite in infections of the skin, soft tissues, and nails. Its pressence has been documented in cases of Blastomycosis, Candidiasis, Chromoblastomycosis, Histoplasmosis, Entomophthoramycocis, Phaeophphomycocis and Keratomycosis.

      Curvularia: a fungus that is found in the soil of areas with very moist tropical climates. It is an opportunistic pathogen that is found as a parasite on tropical plants and agricultural crops, including beans, cotton, rice, barley, and corn, plant matter, and birds. The spores are easily made airborne, and they can cause respiratory problems for many people.

      Drechslera: a fungus that is an opportunistic pathogen. It typically infects those who are immuno-compromised. Various species within this genus have been documented in cases of phaeohyphomycosis, including cutaneous, subcutaneous, and systemic infections that develop dark-walled dematiaceous sptate mycelial elements in host tissues.

      Epicoccum: an airborne fungus commonly found in soil. It is also found in polluted water and carried by insects. It grows on plant leaves, decaying plant materials, uncooked fruit, textiles, paper products, and human skin. The health symptoms associated with exposure to it are congestion and runny nose, which increase in the summer and early fall.

      Fusarium: a common opportunistic pathogen that is a saprophyte of plants. Fusarium spores are easily made airborne and found as an infection-causing parasite in various lesions of the skin, soft tissues, and nails.

      Geotrichum or Gliocladium: fungi that are similar and commonly found in soil and on decomposing plant matter, damp canvas, wood, and paper products. They are opportunistic pathogens that are a common cause of allergenic response for sensitive individuals.

      Helminthosporium: a fungus commonly found on cereal grain plants such as corn, rye, wheat, and oats. Inhalation of its mold spores causes multiple health symptoms.

      Humicola: a fungal organism that is a known and aero-allergen. Even in low concentrations, humicola can cause allergic reactions in hypersensitive individuals. Chronic exposure at moderate to high airborne concentrations may also result in sensitization and the development of allergic disease in previously unaffected individuals.

      Monilia: a soil-borne organism that frequently grows on bread and pastries. Extracts of Monilia produce skin test reactions in a moderate number of mold-sensitive patients.

      Mucor: a phycomycete that is normally found in soil. It is frequently found in barnyards, where it grows on animal waste. It is widespread and elicits allergenic responses in a moderate number of mold-sensitive individuals.

      Neuspora: a soil-borne organism that produces a tremendous quantity of spores and that grows on bread and pastries. Extracts of neuspora produce skin test reactions in a moderate number of mold-sensitive individuals.

      Nigrospora: an airborne fungus that is usually found in areas of high relative humidity. It is very active in the spring and fall.

      Oldiodendron: a known and documented aero-allergen. At low airborne concentrations, Oidiodendron may cause allergic reactions in hypersensitive individuals. Chronic exposure to moderate to high airborne concentrations may cause sensitization and development of allergic disease in previously unaffected individuals.

      Paecilomyces: a fungus found in soil. It grows on damp paper and decaying vegetable matter. Its effects–hypersensitivity and respiratory disease–are similar to those caused by exposure to Penicillium and Aspergillus.

      Penicllium: a known and documented aero-allergen. It is commonly found in soil, and it grows readily on fruits, breads, cheeses, and other foods. An opportunistic pathogen, it produces mycotoxins that are toxic to humans. Penicillium is an agent for hypersensitivity diseases and is a parasite in infections of skin lesions, soft tissues, and nails. Mutant strains of Penicillium are utilized to produce the antibiotic Penicillin.

      Phoma: a fungus that grows readily on most paper products, such as magazines and books. It grows on some paints and green plants. Phoma is widespread in nature and frequently produces a skin rash or other reactions in mold-sensitive individuals.

      Pullularia: a fungus that is normally found in soil. It grows on decaying vegetation, plants, and caulking compounds. It frequently occurs in large numbers, but has less clinical significance than other fungi.

      Rhizopus: a phycomycete that grows readily on bread, cured meats, and root vegetables indoors. It grows on a variety of plants in nature and is widespread in its distribution. It elicits an allergenic response in a moderate number of mold-sensitive individuals.

      Rhodotorula: a common yeast that is a frequent saprophyte on airborne dust, skin, and the macosae. It is a common cause of respiratory problems in humans.

      Scopulariopsis: a fast-growing common fungus that is a saprophyte in nature. It can cause nail infection as well as deep-seated granulomatous lesions.

      Stemphylium: a fungus found in tropical areas and in areas of high relative humidity, especially near bodies of water. It grows in the soil of grass and grain lands, forests, polluted water, bark, decaying plant materials, cotton fabric, canvas, damp paper, and books. In those allergic to airborne spores, it can cause symptoms, and it is an agent for hypersensitivity diseases.

      Trichoderma: a fungus that is found mainly on decaying wood. It is also found on damp cotton and wool and in damp areas such as basements. It may be the most reacting mold, indicating a sensitizing ability in some people.

      Unocladium: a fungus that is a known aero-allergen and an opportunistic pathogen. Exposure to this fungus may cause allergenic reactions, sensitization, Blastomycosis, Candidiasis, Chromo-blastomycosis, Histoplasmosis, Entomophthoramycocis, Phaeophphomycocis Keratomycosis.

      Verticillium: a fungus, similar to Penicillium, that is found in soil. It is an agent for hypersensitivity diseases.

      Sterile hyphae: a fungus that did not produce spores in the laboratory culture. Without sporulation, a formal scientific classification cannot be determined.